Ventilated facade



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Ventilated facades got their name after theventilated layer i.e. the layer of air between the insulation material and theexternal, decorative layer. Today, they represent one of the most frequentlyused methods of veneering external walls of business buildings.

Basicelements of a ventilated facade and their functions: 

  • Supporting substructure - horizontal and vertical profiles

Substructureis mechanically tightened to a supporting wall, in accordance with instructionsof the facade manufacturer. The role of the substructure is to support theexternal, facade covering and to transmit the load generated by wind to thebearing structure.

  • Knauf Rock rock mineral wool insulation material


Thermalinsulation material in a system of ventilated facades must be rigid and properlybonded in order to prevent tearing and dispersion of the material due to anystronger air flow in the ventilated layer. Higher density of insulationmaterial also prevents the infiltration of cold air into the material.

Rock mineral wool thatis to be used depends on the building height and the air exchange in the ventilatedlayer; recommended types of rock mineral wool:

  • NaturBoard VENTI PLUS in all systems of ventilated facades  
  • NaturBoard VENTI in a system of thoroughlyventilated facades up to 12m high.



Rock mineral wool slabs are placed close to each other, without any clearances between them. Theslabs are mechanically tightened in order to obtain the effect of pressurizingthe slabs against the supporting wall. Specially designed screw anchors forventilated facades should be used, with head diameters of ø 90mm. Therecommended number of screw anchors is 6pc/m2 while in edge zonesthe number should be increased because of a stronger wind flow (all inaccordance with recommendations of the screw anchors manufacturer).

Slabs may beadditionally lined with glass quilt (the lined side of the slab should face theventilated layer) in black or white colour depending on desired visual effect.By this, the following characteristics are improved:

  • Resistance to longitudinal air flow: glass quilt protects the slab surface against stronger air flow within the air layer  
  • Hydrophobic nature of slabs:in this way rock mineral wool slabs are additionally protected against direct weathereffects as of rain or snow, due to possible larger joints between slabs of theexternal veneer. 


  • Ventilated layer

Theventilated layer size is min. 2cm (in accordance with recommendations of the facademanufacturer). The role of this layer is to take diffusive moisture out of thebuilding (from internal, warmer space to outer, colder environment – that iswhy a vapour barrier is not necessary), as well as to eliminate water that maypenetrate the external veneer. In summer, it prevents heat to get into thebuilding (decreases the heating of the basic wall mass), while in winter it isan additional thermal insulator.

  • External, decorative layer

Thislayer defines the visual appearance of the building and it may be constructedof glass, marble, stone, alukobond, ... The role of this layer is to provideprotection against the sun, rain and other atmospheric influences. This layeralso receives and transmits loads generated by wind to the supportingstructure.